Cushioning unit



y 1941- E. H. BLATTNER CUSHIONING UNIT Filed July 27, 1938 s Sheets-Sheet 1 j v i mm 7 ll/frs/w if J/v/L H545 7'7'NER y 1941- E. HJBLATTNER 2,

CUSHIONING UNIT Filed July 27, 1938 3 Sheets-Sheet 2 E. H. BLATTNER May 20, 1941.

. CUSHIONING UNIT Filed July 2'7, 1938 3 Sheets-Sheet 3 mm EN of a superimposed load.

' Patented May 20, 1941 CUSHIONING UNIT Emil Blattner, Rochester, Y., assignor to The Symington-Gould Corporation, Rochester,

N. Y., a corporation of Marylan'ji" I Application July 27, 1e38, stream 221,612 24 Claims. (o1. act-c) The present invention relates to a spring or cushioning unit or device adapted to be used in combination with resilient means of a different character for supporting a superimposed load or bolster member of a railway truck.

' An object of the instant invention is the provision, in a spring or cushioning unit, of an association of instrumentalities whereby a central or axially disposed resilient element is initially compressed, and when the unit is placed in service the resilient element is further energized, to thereby prevent a near permanent set taking place in the element while the unit is retained in stock or reserve supply prior to its being placed in service.

Another object of the invention is to resiliently and frictionally resist the compressive movement of a cushioning device which has means associated therewith to decrease the frictional forces during an expansive movement of the device.

A further object of the invention is to energize an axially disposed resilient element of a cushioning unit in such a manner as to gradually increase the radial forces exerted by said resilient element and consequentially increase the frictional forces resisting the compressive movement of the unit. 7 v

Fronnan inspection of the accompanying drawings which form a part of the present specification the above-recited as well as numerous other objects will become apparent.

By now considering the several figures of the drawings which disclose exemplary forms of the invention, it will .be found that:

Figure 1 is a vertical sectional view of a cushioning device embodying a type of the present invention and illustrating the associated parts in a relation they attain when the device is free from a superimposed load.

Figure 2 is a vertical sectional view of the de-" vice disclosed by Figure 1 but showing the component parts thereof in a relation they may assume when a superimposed load is applied. to the device. v

Figure 3 is a horizontal sectional View taken alongthe lines 3-3 of- Figure 1 and looking in the direction of the arrows.

Figure 4 is a horizontal sectional view taken along the lines 44 of Figure 1 and looking the direction of the arrows.

Figure 5 is a vertical sectionalview of a cushioning unit embodying another type of the present invention and showing the parts thereof in their respective relation when the unit is relieved Figure 6 is a vertical sectional view of the unit disclosed by Figure 5 and illustrating the parts of the unit in the respective relation'they may assume when a load is applied to the unit.

Figure 7 is a horizontal sectional view taken along the linesl-I of Figure 5, looking in the direction of the arrows.

Bynow referring to the drawings in detail, wherein like reference characters indicate like parts, and initially considering the structure disclosed by Figures 1 to 4, inclusive, the cushioning unit or device is generally designated by the numeral I. constituting a portion of the unit is a tubular or barrel member 2 comprising a sleeve or casing 3 having a radial flange 4 extending therefrom adjacent one end thereof. The casing or sleeve is desirably formed with an axial bore 5 which is preferably machined to present a smooth or even inner cylindrical surface 6. Thebore extends entirely through the sleeve in order to facilitate the process of machining. Positioned in the bore 5 adjacent the flanged end of the sleeve in a closing piece or end plate I which is applied to the sleeve under pressure so as to prevent it from being displaced. The closing piece is formed with an inwardly convoluted portion 8 to present an outwardly facing relief 9- which'forms a receptacle for a lug (not shown) provided on a superimposed member for retaining the associated extremity of the unitin a predetermined position. It will, of course, be clearly understood that the closing piece may, if desired, be formed integrally with the sleeve.

Intimately associated with the sleeve is a plurality of counterpart segmental friction shoes l0 each of which includes a vertically disposed stem portion 1 I and-a radially extending flange or lug l2 positioned adjacent one or the lower extremity of the stem portion and directed outwardly of the device. The shoe stems are arranged to-partially extend into the sleeve bore so as to be capable of movement in either direction and are desirably formed as a ring sector in horizontal section, as most clearly illustrated in Figure 3, to form, in assembled relation, a cylin- 'drical housing provided with an outer surface l3 thereof in bearing relation and coaxially formed with the sleeve surface 6. Positioned adjacent the flanged end of the shoes is an annular or ring member l4 having an undercut or relief IS on its underside to accommodate the'shoe flanges. It will be noted that the annular member and shoes are interlocked so as to allow the former 'to act as a medium by which the shoes are urged Gil" longitudinally of the device with respect'to the drical member II .which is supply for a .in service.

tubular member during the expansive movement of the device.

Forming a resilient means which assists in resisting the compressive movement of the unit, as well as forming the primary meansbywhich the unit is expanded or returned to normal position, is'a helical or coil spring l6 extending circumjacent the sleeve 3 in spaced relation thereto and reacting against the tubular member flange l and annular member [4. The term normal" is herein used to denote a unit or device having the component. parts thereof in the respective relation they assume when the unit is subjected to the normal pressure ofa superimposed load or bolster such as disclosed by Figure 2 of the drawings.

Positioned within the shoe stem formed housing and disposed axially of the'unit is a cylinformed of rubber or any other inherently resilient material which may be employed to perform the function intended. The cylinder I'I, before application to a unit, is desirably formed of a circumferential dimenthe cylinder engaging portion of the assembled shoe stems,and in this manner the cylinder is pre-formed so that, upon application to the unit, it is initially compressed between the shoe stems and thereby capable of resiliently urging the shoe stems radially of the unit and into intimate contact with the sleeve or casing 3. By reason of this recited arrangement, the movement of the shoe stem surfaces I3 over the casing surface 6 will create frictional forces, retarding both the compressive and expansive movement of the unit or device. It will be noted that, when removed from a unit, the cylinder is formed with plane end surfaces substantially perpendicular to the longitudinal axis thereof and, upon assembly with the associated elements of the unit, the rubber or resilient mass flows outwardly of theends tov present upper and surfaces l8 and 18 respectively. It will, of course, be understood that the end surfaces of the cylinder maybe so pre-formed to present end surfaces of any desirable configuration, and it is not the present intention to limit the cylinder end surfacesto a spherical andconvex disposition.

It has been rial, when subjected to constant compressive, tensional or shear forces, normally has a tendency to assume a near-permanent setwh'ereby the rubber mass loses a portion of its inherent re silient value for accomplishing thepurpose intended. Cushioning units of the present type are at times assembled by the manufacturer and lower spherically convex end found that rubber'or similar matepositioned in spaced relation to and inwardly of the shoe stems. The plunger circular portion forms a receptacle for an associated positioning means (not shown) for retaining the lower extremity of the unit ,ina predetermined position. and preventing the accidental displacement thereof. The plunger circular portion is closed at one end thereof by means of a convex portion 2| which has an inwardly facing spherical convex surface 22 slightly contacting the lower spherical end surface I! of the cylinder II when the unit is not in service, as most clearly illustrated in Figure 1. So as to limit the movement sion greater than the corresponding dimension of of the plungeroutwardly of the device there is provided radially disposed lugs or fingers 23 extending outwardly of the plunger circular portion and into apertures 24 inthe shoe stem. The apertures 24 are positioned intermediate the ends of the shoe stems and are formed as recesses along the transverse edges of the stems. The apertures or recesses are elongated so as to allow. a free unrestricted movement of the plunger with respect to the shoes inwardly of the device. The plunger circular portion is arranged and constructed so as to have a portion thereof extend outwardly of the device beyond the flanged end of the friction shoes when the unit is not in service so that, upon application of a superimposed load to the unit during service,

the plunger will be urged inwardly of the device to actuate or energize the cylinder l1 and thereby materiallyincrease the component radial pressure acting on the shoe stems and consequentially the frictional forces which act upon the stem surfaces I3 and-sleeve surfacei when the shoes and tubular member are moved'with respect to one another.

The intimate convex surfaces l8 and 22 provide for gradually increasing the radial pressure exerted-by the cylinder l1, and by the same token when the plunger moves outwardly of the device the radial pressure will be gradually decreased. If, however, during service, the frictional forces are greater than the expansive capacity of the helical spring to such a degree that the helical spring is incapable of moving the friction shoes away from the tubular member, the energized cylinder will urge the plunger outwardly of the device, thereby decreasing the frictional forces by an amount sufflcient to allow the helical spring to completely expand the unit. The circular portion of the plunger has the outermost end thereof flared, as at 25, to increase the outer or spring plate bearing area of the plunger.

Positioned in the close proximity of the end surfaces llof the cylinder is a beading, stationshipped to the consumer, the latter of whom oftentimes retains the units in stock or reserve period of-time before placing them providedadjacent the shoe flanged end of the device a plunger or cylinder actuator is which is adapted to move longitudinally or axially of the deviceinto the shoe stem formed housing; The plunger preferably comprises a cylindrical.

or circular portion 20 formed coaxial with the shoe stems and tubular member sleeve and is If the resilient cylinder were subary means or hearing shoulder 26 extending inwardly of each shoe stem from adjacent the end thereof opposite from the flanged end. The purpose of the shoulders 28 is to reinforce the shoe stems as well as present an abutment for the periphery of the cylinder end I8. When the unit is subjected to service loads the plunger moves inwardly of the device, displacing the resilient mass vertically of the unit, and by reason of the bearing shoulders 26 only partially restricting the passage of the resilient mass, the cylinder will be placed in shear.

The closing piece convoluted portion 8 has an inwardly facing spherical convex surface 21 normally inspaced relation to the convexend surface ll of the cylinder I'I. The surfaces 21, and I8 are'arranged and'disposed so that, after a predetermined compressive movement of the unit,

sirably pre-formed with end surfaces disposed in a plane substantially perpendicular to its longitudinal axis so that, upon compression the cylinder for application to the unit, the resilientmass will flow outwardly of the unconfined ends thereof to present upper and lower spherical convex surfaces l8 and I8", respectively.

Like the previously described structure, the' present. embodiment has the component parts thereof arranged so that the cylinder is relieved of its service load while being retained in reserve cludes a tubular or barrel member '4." having a sleeve or casing 3 terminating in a top or ra- The sleeve dially disposed flange or 'shelf 4 3 is provided with an axially disposed bore 5 which is preferably machined and extends entirely through the casing. The bore 5 is closed adjacent the flanged end of the casing bymeans of a closing piece or end plate I which is applied to the casing under pressure, the relative diameters of the closing piece and bore being of a dimension to require such an application. In this manner the end plate com pletely prevents the entrance of foreign subsupply or stock. In this manner the cylinder is under very little compression while the unit is not in service, and any tendency of the cylindrical mass to set will be delayed. To accom- "plish the above, a plunger Ill is positioned intermediate the shoe stems adjacent one or the 'flanged end thereof and is arranged to move axially of the device to energize the resilient cylinder. The plunger desirably comprises a circular or cylindrical portion 20 of a diameter stance to within the sleeve as well as prevents an accidental separation between the closing piece and sleeve.' The closing piece is provided with an outwardly facing recess 9 which may accommodate a positioning means on an associated structure to retain the upper extremity of the unit in a predetermined position.

Arranged to move relatively to the tubular member and axially of the device is a plurality of substantially counterpartsegmental friction shoes Ill each of which includes a stem portion sleeve 3, to thereby provide an appreciable" amount of bearing area between the shoe stems and sleeves. The shoes are provided withradial flanges or legs, [2 extending outwardly of the stems from adjacent one or the lower extremity thereof. Superimposed upon theshoe flanges is an annular or ring member Wkwhich has an' undercut or relief portion l5 formed on its 5 outer side to accommodate or form a pocket for the shoe flanges. against the tubular member shelf 4 and annular member M is a coil or helical spring. Hi arranged circumjacent the sleeve 3 in spaced relation thereto. When the unit has'been compressed and subsequently re'lievedof a super.- imposed load the helical spring will urge the tubularmember and .shoes apart to expand the unit and return it to its normal position.

Positioned between the shoe stems is a cylin-.

unit, is under an initiala'compression and capable of urging the shoe stems radially of the device and the stem surfaces I 3 into intimate contact with the sleeve surface 6 The cylinder is de- In this manner the cylinder, when appliedto a Interposed between and acting less than the inner diameter of the assembled shoes so as to. be capable of an unrestricted movement longitudinally of the device. The plunger circular portion is desirably closed at its inner extremity by means of an arcuate plate portion 2t which is provided with an inwardly facing spherical surface 22*" the latter of which merely contacts the lower cylinder end 18 when the unit is'not in service. Lugs or fingers 23 extend radially of the plunger circular portion and project into suitable apertures 24*- in the shoe stems positioned adjacent the flanged end thereof to form guiding means during the axial movement of the plunger as well as retain the plunger in assembled relation with the associated structure of the unit. The apertures are positioned along the lateral orwtransverse edges of the shoe stems and are desirably elongated in order to allow movement of the plunger inwardly of the device while limiting movement of the plunger in the opposite direction. plunger circular portion is desirably flared, as at 25, to thereby increase the outer bearing area of the plunger. 7

When a unit of the present structure is not in service the plunger circular portion has a portion thereof extending beyond the flanged end of the friction shoes and annular member, as most clearly illustrated in Figure 5, and while the plunger is thus positioned the resilient cylinder is relieved of service loads and merely under initial compression. However, when the unit is placed in service and a superimposed load is applied thereto the plunger will be urged or moved axially' of the device to energize the cylinder and substantially increase the component radial pressure exerted against the shoe stems. This latter pressure will increase the frictional forces acting upon the stem surfaces Iii and sleeve surface 6 when the shoes are moved relatively to the sleeve during an expansive or compressive movement of the device. It will be noted that by reason of th intimately related convex surfaces It and 2 2 he frictional forces of a completely compressed unit will be gradually decreased in order to allow relativemovement between the shoes and tubular member in a di.

rection away-from one another during the expensive movement of the device if the frictional forces are sufficiently great to prevent the helical spring from returning the unit to expanded position; The shoe stems are provided with inwardly directed flanges 2B which arepositioned adjacent The the other or top extremity thereof and are triangular in form when viewed from the top,.as most clearly illustrated in Figure '7. Reacting against the vertical displacement of the resilient mass forming the cylinder, during the compressive'movement of the unit, isa substantially stationary member or bearing pad 26'- which is interposed between the shoe flanges 28 and the upper surface ll of the cylinder. The bearing pad is provided on one side thereof with a conically formed surface 19 which bears directly against a correspondingly formed surface 30 on the shoe flanges 20. This particular disposition of surfaces 29 and 30 maintains the bearing pad in a predetermined position and prevents shifting thereof laterally of the device. The bearing pad 26' has an inwardly facing spherical convex surface 3| in intimate contact with the upper convex surface [8'' ofv the cylinder-so that, during a compressive movement of the device, the cylinder will be gradually compressed to correspondingly increase the component radial pressure exerted against the shoe stems, and by thev same token the component radial pressure may be gradually decreased during the expansive movement of the device. It will be observed that the component parts of the structure under immediate consideration are constructed and arranged to place the cylinder under compression, while the parts of the previously described structure are so arranged that the cylinder is initially under compression, and when the unit,is placed in service the resilient mass is displaced in a manner to develop shear stresses in the cylinder in addition to the compressive forces. I

- It will, of course, be clearly understood that it is not the present intention to limit the invengage said rubber means to additionally energize said rubber means after a predetermined com- 'pressive movement of said cushioning unit.

movable means bearing against said resilient means so that, upon a compressive movement ,of said device, said movable means will be urged entirely within theconfines of said shoes and energize said resilient means to increase the radial pressure 'of said shoes against said tubular member.

4. A cushioning unit, in combination, a tubular member} segmental shoes having stem portions thereof extending into said tubular member, flan es extending radially of said shoe stems in spaced relation to said tubular member, annular means extending circ'umjacent said shoe stems and bearing against said shoe lflanges, spring' means interposed between said tubular and annular members, rubber means interposed between said shoe stems and urging them radially into plunger interposed between said shoes having a' tion to the illustrated and described structures but. that various alterations and changes may be made thereto without departing from within the spirit and scope of the appended claims.

w I claim:

1. In a cushioning unit, in combination, a tubular member, segmental shoes movable relative to said tubular member, an. annular member in bearing relation with said shoes, spring means positioned so as to react against said tubular and annular members for urging them apart, resilient means arranged to urge said shoes into engagement with said tubular member, a plunger positioned adjacent the extremity of said shoes and having a surface thereofin'bearing relation with said resilent means, said plunger having a'portion thereof extending beyond said shoes and being movable relative to said shoes whereby, upon a comp essive. movement of said unit, said plunger 'within the confines of said shoes to energize said resilient means. I 2. In a cushioning unit, in combination, a bar- "rel member, segmental shoes movable relative to said barrel member, an annular member extending circumjacent and in bearing relation withsaid shoes, spring means adapted to react against said barrel and annular members forurging said ill move inwardly of said unit entirely bearing relation with said tubular member, a

surface thereof in bearing relation with said rubber means, said plunger having lugs outstanding therefrom and extending into apertures in said shoestems to limit the travel of ,said movable means outwardly of said unit, said plunger,

upon a compressive movement of said unit, being adapted to move entirely within the confines of said shoes to energize said rubber mem 5. In a resilient device, in combination, a tubular member, a plurality of segmental shoes partially extending within and movable'relative 3 to said tubular member, spring means circumjacent said tubular member in spaced relation thereto and adapted to urge said tubular member and shoes apart, bearing means associated with said shoes adjacent one. end thereof, resilient means interposed between said shoesfor urging them radially of the device into bearing relation with said tubular member, said resilient means having an end portion in intimate contact with barrel member and shoes apart, rubber means v interposed between said shoes for urging them radially into bearing relation with said barrel member, a plunger movably associated with said shoes adjacent one end thereof and in bearing relation with said "rubber means whereby, upon an initial compressive movement of said unit, said plunger will move relative to said shoes and energize said rubber means, and means associated with said barrel member adapted to ensaid bearing means, movable means associated with said shoes adjacent the other end thereof and having outstanding lugs projectingthrough apertures inYsaid ishoes, said movable means bearing against said resilient means whereby, upon a compressive movement of said device, said movable means will urge said resilient means against said bearing means to sub ect said resilient means to shear stresses. I

-6. In a cushioning unit, in combination, a tubular member, segmental shoes having stem portions thereof extending'into said tubular member, flanges extending radiallyof said shoe stems, annular means bearing against said shoe .flanges, spring means interposed between said [tubular member and annular means, resilient means interposed between said shoe stems and urging them radially into bearing relation with said tubular member, a plunger interposedbctween said shoes having 8 convex surface thereof in bearing relation with a convex surface on said. resilient means, said plunger having lugs outstandingrtherefrom and extending into slots in said shoe stems, said plunger, upon a compressive movement of said unit, being adapted to move entirely within the confines of said shoes said shoes'for urging them radially of the device into bearing engagement with said tubular member, said resilient means bearing against said stationary means, movable means associated with said shoes adjacent the other end thereof and having outstanding lugs projecting through slots in said shoes, said movable means bearing against said resilient means so that, upon a compressive movement of said device, said movable means will urge said resilient means against said stationary means, and means associated with said tubular member adapted to contact said resilient means to further energize the latter after a predetermined compressive movement of said device.

8. In a cushioning unit, in combination, a tubutherethrough, a,closing 'piece positioned in said plunger positioned adjacent an extremity of said shoes and having a convex surface in bearing relation with said resilient means, said plunger being movable relative to said shoes whereby, upon a compressive movement of said unit, said plun-' ger will move inwardly of said unit and gradually energize said resilient-means.

11. In a cushioning unit, in combination, a tubular member, shoes having portions thereof extending within said tubular member, springv means acting between said tubular member and shoes for urging them apart, a compressible cylindrical member interposed between said shoe portions for urging them radially and into engagement with said tubular member, a plunger having outstanding means extending through I apertures in said shoes adjacent one end thereof lar member having an axial bore extending bore adjacent one end thereof, segmental shoes having portions thereof extending into said bore, spring means arranged to urge said tubular member and shoes apart, means extending inwardly of said unit from adjacent one end of said shoes,

a resilient cylinder positioned axially ofsaid unit for urging said shoes radially of the unit and into bearing relation with said tubular member, a

plunger positioned between and movable relative to said shoes adjacent the other and thereof whereby, upon a compressive movement of said unit, said plunger will urge said cylinder longitudinally of the device and said cylinder will react against said shoe means.

9. "m a cushioning unit, in combination, a tubular member having an axial bore extending therethrough, a closing piece positioned in said bore adjacent one end thereof, said piece having a convex surface facing inwardly of the bore, segmental shoes having portions thereof extending into said bore, spring means arranged to urge said tubular member-and shoes apart, means extending in ardly of said unit from adjacent one end of sai shoes, a resilient cylinder interposed,

between ,said shoes for urging them radially of the unit and into bearing relation with said tubular member, a plunger positioned between and movable relative to said shoes adjacent the other end thereof whereby, upon an initial compressive movement of said unit, said plunger will urge so as to normally restrict the movementof the plunger outwardly of the unit while permitting movement of the plunger inwardly of the unit, and means associated with said tubular member adapted to additionally energize said compres-. sible cylindrical member after a predetermined compressive movement of saidcushioning unit.

12. In a cushioning device, in combination, a tubular member, shoes movable longitudinally of the device and extending into said tubular member, spring means acting between said tubular member and shoes, a compressible cylinder. 1 positioned between said shoes for urging them into engagement with said tubular member, a

pluhger positioned adjacent one end of said shoes having a portion thereof extending out-' wardly of said shoes, said plunger being adapted to develop shear stresses in said cylinder when a load is applied to said device.

13. In a cushioning device, in combination, a tubular member, shoes movable longitudinally of, the device and extending into said tubular member, spring means acting between said tubular member and shoes, a compressed rubber cylinder positioned between said shoes for urging them radially into engagement with said tubular member, a plunger positioned adjacent one end of said shoes and having a portion there- 7 of extending outwardly of said shoes, and'said' plunger engaging said cylinder and being adapted to move inwardly of the device entirely within the confines of said shoes during a compressive movement thereof to thereby increase the radial pressure exerted on said shoes. I/

14. In a cushioning device, in combination, a tubular member, shoes movable longitudinally of the device and extending into said tubular member, spring means acting between said tubular member and shoes for urging themapart, a compressed rubber cylinder positioned between said shoes and urging them into engagement with the tubular member, bearing shoulders on said shoes adjacent one end of said cylinder, a movable said cylinder against said shoe means and, after a predetermined compressive movement of the unit, said convex surface will engage and gradually energize said cylinder.

10. In a cushioning unit, in combination, a

tubular member having a machined bore extending therethrough, a removable closing'piece occupying said bore adjacent one end thereof, segmental shoes movable relative to said tubular member, an annular member in bearing relation with said shoes, spring means arranged between said tubular and annular members for urging said tubular jinember and shoes apart, transplunger adjacent the otherend'of said shoes havinga portion thereof extending beyond-the corresponding end of said shoes so that, when said unit is initially compressed, said plunger will urge said cylinder into engagement 'with said shoulders and thereby subject said cylinder tb shear stresses. i

15. In a cushioning device, in combination, a tubular member, shoes movable longitudinally of the device and extending into said tubular member, spring means acting between said tubular member and shoes for urging them apart, a compressed rubber cylinder positioned beversely acting resilient means urging said shoes into engagement with said tubular member, a

corresponding end of said shoes so that, when said unit is initially compressed, said plunger will urge said cylinder into engagement with said bearing pad and thereby increase the compressive forces in said cylinder,

16. A tubular member fora cushioning unit comprising a sleeve having a machined bore extending completely therethrough, a radial flange adjacent one end of said sleeve forming a ledge for an associated spring, and a closing piece applied to said sleeve under pressure .andpositioned adjacent the flanged end of said sleeve.

17. A tubular member for a cushioning unit comprising a sleeve portion having a machined bore extending therethrough, a radial flange adjacent one end' of said sleeve to form. a ledge for an associated spring, and a closing piece applied to said sleeve under pressure-and positioned adjacent the flanged end of said sleeve,

said closing piece having a spherical convex surface adapted to engage-and gradually energize an associated resilient element.

18. Ina cushioning device, in combination, a tubular member, segmental shoes positioned;

within and movable relatively to-said tubular member, spring means adapt d to-urge said tubular member and shoes apart, a compressed resilient cy inder interposed between said shoes and urging them radially of the device into intimate contact with said tubular member and movable means associated' with an extremity of said] shoes and having a portion thereof extending beyond said shoes outwardly of the device, said movable member, upon an initial compressive movementof said device, being urged within the confines of said shoes to additionally energize said resilient cylinder.

19. In a-cushioning device, in combination, a

tubular member, segmental shoes positioned within and movable relatively to said tubular member,- a compressed resilient cylinder interposed between said shoes and urging'them radially of the device into intimate contact with said tubular member, said resilient cylinder having a downwardly facing convex surface, and movable means associated with an extremity of said'shoes and having a convex surface iirengagement with said cylinder convex surface, said movable means. being adapted to travel inwardly of said device during a compressive movement thereof to gradually energize said resilieht cylinder.

20. In a cushioning device, in combination, a tubular member, shoes movable longitudinally I of the device and .extending' into said tubular 7 member, spring Ineansacting between said tubular member and shoesfor urgingthem apart, a

.able plunger adjacent the other end of said shoes having a portion thereof extending beyond the corresponding end of said shoes so that, when said unit is initially compressed, said plu'n er .will urge said cylinder against said convex rface and thereby gradually energize said cylinder.

21. In a cushioning device, in combination, a tubular member, shoes movable longitudinally of the device and extending into said tubular member, a compressed rubber cylinder having oppositely disposed arcuate surfaces and being positioned between said shoes urging them outwardly of the device into engagement with said tubular member, flanges on said shoes adjacent one end thereof, a bearing pad underlying said flanges and having a convex surface in intimate contact with one of said rubber cylinder convex surfaces, anda plunger adjacent the other end of said shoes having a convex surface in intimate contact with the other of said rubber cylinder convex surfaces, said plunger being adapted to move inwardly of the device to graduallyenergize said rubber cylinder.

22. 7:1 a. cushioning device, in combination, a tubular member, shoes .movable longitudinally of the device and extending into said tubularmember, a compressible cylinder positioned between said shoes for urging them into engagement with said tubular member, a plunger positioned adjacent one end of said shoes being adapted to develop shear stresses in said cylinder upon. a compressive movement of said device, and means on said tubular member adapted to engage and energize said cylinder after a predetermined compressive movement of said device.

' 23. In a. cushioning device, in combination, a tubular member, shoes movable relative to and extending into said tubular member, a compressible means positioned between said shoes for urging them into engagement with said tubular member, and a movable member positioned adiacent one end of said device and being'adapted to develop shear stresses in said compressible means upon an initial compressive movement of said device.

24. In a cushioning device, in combination, a

barrel member, shoes movable longitudinally and transversely of said; device and extending into said barrel member, a rubber means posi- 

